Engine Arm facts for kids

Quick facts for kids Engine Arm
The roving bridge at the junction with the Old Main Line
Specifications
Length	0.5 miles (0.80 km)
Maximum height above sea level	473 ft (144 m)
Status	Navigable
Navigation authority	Canal and River Trust
History
Principal engineer	BCN engineers
Other engineer(s)	Thomas Telford
Date of first use	1790
Geography
Branch of	Birmingham Canal Navigations
Connects to	Old Main Line

The Engine Arm (also known as the Birmingham Feeder Arm) is a short canal near Smethwick, West Midlands, England. It was first built as a tunnel to supply water to a large pumping engine. This engine helped move water to the higher parts of the canal system.

Later, the Smethwick flight of locks (steps of water that boats use to go up or down) was made shorter. This meant the pumping engine could be moved. Part of its water supply tunnel was then opened up and made wide enough for boats. This allowed coal for the engine to be brought by barge. The Engine Arm also supplied pumped water to the Wolverhampton level, which was 473 feet (144 m) high.

Between 1825 and 1830, the famous engineer Thomas Telford extended the arm. He wanted to bring water from Rotton Park Reservoir (now called Edgbaston Reservoir) to the Old Main Line of the BCN Main Line Canal. Telford also added the amazing Engine Arm Aqueduct. This structure carries the Engine Arm over his new main canal line, which was built 20 feet (6.1 m) lower. Today, the Canal and River Trust manages the arm. The basin at the end of the arm is now used for boats to moor (park) their homes.

History of the Engine Arm

Building the First Canal and Engines

When the Birmingham Canal was planned in 1767, the engineer James Brindley hoped to dig a tunnel through a hill near Smethwick. However, tests showed the ground was too soft and sandy for a tunnel. So, Brindley suggested building the canal over the hill instead. This meant using locks to lift boats up and down. Because there wasn't much water nearby, he also suggested using "fire engines" (early steam engines) to pump water up to the highest part of the canal.

This plan led to the Smethwick flight of six locks on the east side and the Spon Lane flight of six locks on the west side. The canal opened on 25 March 1772. The first pumping engine was built by Boulton and Watt and started working in April 1778 at Spon Lane. It pumped water back up to the summit (the highest level). Because it worked so well, a second engine was ordered for the Smethwick end. This engine was placed about 0.75 miles (1.2 km) from the summit. It pulled water from the bottom of the locks through a tunnel and sent pumped water to the top level through another tunnel.

Lowering the Canal and Moving the Engine

The highest part of the canal was only about 1,000 yards (910 m) long. As more boats used the canal, this short section caused long delays. In 1786, the canal company decided to lower the summit level to 473 feet (144 m), which was the same as the Wolverhampton Level. The company's own engineers did this work.

The top three locks at each end were filled in. However, three new locks were built next to the original ones at the Smethwick end. The Spon Lane engine was no longer needed and was sold to the Dudley Canal. The exact spot of the first Smethwick pumping station isn't fully known. But around 1790, the engine, now called the Smethwick Engine, was moved closer to the canal. Part of the existing water supply tunnel was reused. This feeder tunnel was made wide enough for boats at that time. This way, coal could be delivered to the engine by barge.

The engine now only had to lift water by 20 feet (6.1 m) instead of 38 feet (12 m). The old pump was moved, and a new, larger pump was installed. By 1803, the engine needed repairs, which Boulton and Watt carried out. A second engine was ordered in February 1804 and started working in May 1805.

Telford's Improvements and the Aqueduct

By 1824, the Birmingham Canal Navigations had over 70 miles (110 km) of canals. They also connected to many other canals. But a new threat appeared: a railway was planned from Birmingham to Liverpool. To compete, the canal company hired Thomas Telford to suggest improvements.

Telford recommended building a new reservoir at Rotton Park to provide more water. He also suggested making the main canal line straighter and lower by digging deep channels. This new line would avoid the Smethwick locks. The reservoir was built, and the main line improvements were finished in September 1827. Near Smethwick Summit, Telford's new main line ran close to James Brindley's Old Main Line, but it was 20 feet (6.1 m) lower.

To get water from the new Rotton Park Reservoir, Telford extended the Engine Arm eastwards. He created a basin (a wider area for boats) beyond the engine house. Water flowed into this basin from the reservoir through a new underground pipe. The Engine Arm was carried over Telford's new canal by the cast iron Engine Arm Aqueduct. This aqueduct was put in place around 1828. Today, it is a Scheduled Ancient Monument, which means it's a protected historical site. The excavated foundations of the Smethwick Engine are also a protected monument.

Later Years and the Smethwick Engine's Journey

Boulton and Watt repaired the original engine in 1853 and fixed problems with both engines in 1876. By 1891, the engines were very old and too expensive to fix. So, in 1892, a new engine house was built near Brasshouse Lane bridge to replace them. This was the last pumping engine installed on this part of the canal. It had two powerful engines that could pump enough water to fill 200 locks every day. These engines were used until 1905, when one was moved. The other engine continued to be used until the 1920s.

The two old beam engines stayed on site for five more years. They were taken apart and the building was knocked down in 1897. The newer engine was sold for scrap metal. However, the older engine was moved by barge to Ocker Hill. It was put back together there so it could be used for demonstrations. It was last steamed (run using steam) in 1919 for a celebration of James Watt.

Henry Ford tried to buy the engine in 1928 for his museum in Detroit, USA. But the company didn't want to sell it. Instead, they sold him a different engine. When Ocker Hill Works closed in 1960, the engine was taken apart again. It was given to the Birmingham Museum of Science and Industry. After being stored for a while, it is now on display in the Power Up Gallery at Thinktank, Birmingham Science Museum.

The Engine Arm Today

The very end of the Engine Arm is now used for residential moorings. This means people live on boats docked there. There is space for 16 boats. The Canal and River Trust manages this area. It includes facilities like a block with services, parking for residents, and electric hook-ups for the boats.

Images for kids

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  Telford's cast iron aqueduct

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  The top of the aqueduct

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  Engine Arm Basin - private moorings at the end of the navigable section